I guess Really... limiting myself mostly to 18mm f/16, the inherent DoF is pretty massive. While I might not be exactly at the hyperfocal distance, it seems to work well enough for landscapes.

Also, I don't think I mentioned earlier, as I have the filter on, I can't see through the viewfinder, so I'm also composing blind too. Point it roughly in the direction you want and repeat to optimise as needed. When there is no real time visual feedback, I'm finding myself doing very badly at keeping the camera level.

Just one more point, can you remove the bayer filter too and mod the firmware so that you get a 12MP 300D. i do not know the sensor construction, but when you can desolder so many connections and cut the packing of the IR filter, may be you can do this too.

If the bayer filter could be removed, it'll still be 6MP. The difference would be those panchromic 6MP will give a higher detailed overall output than the bayer interpolated output.

But there's other problems which limits that usefullness. One is that the longer wavelengths of IR apparently means the diffraction softening kicks in earlier. This seems to be true from my observations as I just don't get real sharpness from any IR shots ever when pixel peeping. Further to that, most IR work is landscapes so would be shot at higher f values for increased DoF, which again is into the diffraction softening region. The higher resolution isn't terribly useful for this application.

Putting the above aside, the final nail in the coffin is that the sensor is its own module. I only removed the filter from the assembly, but the module package doesn't look like the sort of thing you can open up. I can have another look when the time comes to put the filter back in, but pactically I don't expect this to be realistically doable.

Well, you know better.
But, tell me, if the small filters in the bayer matrix are supposed to let only a certain band of wavelength through, how came they are transperent to the IR wavelength. correct me if i am wrong, but i think that only the red filter is letting the low frequency waves to pass while the blue and green filters, which are ment for higher frequencies are just going opaque. But well, thats why we have specialized IR cameras. .

BTW i saw the photographs you have posted (elsewhere), they look quite good. But there, i see the trees are white, which means they should be perticularly hot compared to the surrounding (which is not the case), so my question is, what kind of PP you are doing, are you inverting the colours? or something like that.

This kind of IR photography is known as near IR. The actual IR region is much bigger, stretching into much longer wavelengths. Near IR images are not correlated to the temperature of the subject. The thermal imaging types are longer wavelength. I think I've seen one example where near IR can be used to detect heat, but you don't see much of anything until you get to hundreds of degrees so not practical for anything day to day.

So what is the image actually showing? The intensity of near IR being reflected or emitted by the subjects. Heat sources like filament bulbs, fire or the sun give out lots of IR. Everything else has to reflect it to be seen. It turns out that greenery is a good IR reflector.

The unprocessed image looks mostly red and black. Key to post processing is to set the white balance so that the overall image is white-ish and black. Depending on the camera, you can get different colour tints in this and play with them as you like.

The best reason I heard for this is that although the bayer filter is only supposed to let through RGB, that only applies to visible light. They may or may not let IR through too. As near IR is close to red, most of the energy does appear in the red channel, but the GB channels may pick up other bands of IR too. The IR block filter stops this before it reaches the RGB filter so not a problem normally.

Cutting the filter was both easier and harder than expected. I used a borrowed tile cutter. This scores a weak point in the glass. A bending motion then causes stress, which should follow the line of weakness. As you can see in the shot, it wasn't as straight as it could be.

Not shown, this is of course a different size than the removed IR blocking filter, so I can't fit it in the same mounting exactly. What I can do, and plan to do is to fix the new filter directly on the assembly that holds the sensor. Probably involving glue and tape.

This wont in itself fix the AF offset from before. The IR filter is thinner than the original, also the slight shift in distance from the sensor may or may not make a difference too. I hope to get this done over the next week or so.

I have witnessed diamond tipped glass cutters to work pretty well (i mean straight edges). May be it will take a little more practice and patience.

TIPS:1) Draw a line with a marker where you want to cut, then wet this area with a small ammount of kerosene oil, then with help of a ruler score a line with your cutter. (Kerosene help smooth movement, a sure bet)

2) I the filter glass is acting too brittle, do the bending and breaking operation under water. (you can not imagine how much this can help)

Oh yes! I finally got round to doing phase 2 of the IR modification. That is, I opened up the camera again, put the IR pass filter in front of the sensor, and reassembled everything. It works, and I'm getting some... let's just say interesting results. It is working, but now that I have a working viewfinder I can see what I'm shooting again. Plus, returning the glass in front seems to have made the AF "good enough" to work at shallower DoF. I'll need to sort out the test pics in a moment.